This invention relates to an analgesic composition and method for alleviating pain. More particularly, this invention is concerned with alleviating pain by administering to a mammal exhibiting pain (a) an analgesia-effective amount of at least one analgesic selected from the group consisting of (R)-5-(2-azetidinylmethoxy)-2-chloropyridine, (S)-5-(2-azetidinylmethoxy)-2-chloropyridine and pharmaceutically acceptable salts thereof and (b) an analgesic-potentiating amount for said analgesic of at least one nontoxic antagonist, or blocker, for the N-methyl-D-aspartate (NMDA) receptor.
Administration of opioid analgesics such as morphine remains the most effective means of alleviating severe pain across a wide range of conditions that includes, for example, acute, persistent inflammatory and neuropathic pain. However, the use of opioid analgesics are limited due to side effects such as respiratory depression, constipation and physical dependence. Thus, efforts have been made to develop non-opioid analgesics for treatment of pain that are devoid of the problems associated with the opioid analgesics.
Recently, new members of the 3-pyridyl ether compounds, referred to as (R)-5-(2-azetidinylmethoxy)-2-chloropyridine (also referred to as ABT-594) and its S-enantiomer have been reported as being potent non-opioid analgesic agents. In general, these analgesics are believed to exert their analgesic action via the neuronal nicotinic acetylcholine receptors. The administration of the analgesics can result in pain management without the side effects associated with the administration of the opioid analgesics.